Circulatory System

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Circulatory System

• Blood

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What is the Function of Blood?

• Transport Nutrients
• Glucose, Oxygen, enzymes, Hormones
• Get Rid of Waste
• CO2
• Regulate body temperature
• Protect body from invaders

How much blood do you have?
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Whats in Blood?





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Whats in Blood?

• Plasma
• 92 Water and 8 dissolved fats, salts, sugars,
  and Proteins
• Platelets
• tiny Fragments of Cells. Function in blood
  clotting
• Red Blood Cells
• Hemoglobin is the iron-containing protein
• that gives RBC the ability to carry Oxygen. 
• Hemoglobin gives the RBC their color.
• White Blood Cells
• Protect the body against foreign invaders

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Circulatory System

• Blood Vessels

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ARTERIES, VEINS AND CAPILLARIES

• CLOSED SYSTEM - blood is contained within either
  the Heart or Blood Vessels at all times.
• 2. The blood Vessels help keep the Blood flowing
  in One Direction.
• 3. After the Blood leaves the Heart, it is pumped
  through a network of Blood Vessels to different
  parts of the body.

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What are Arteries?

• carry blood from the HEART TO CAPILLARIES
• Walls are THICK, tough and flexible.
• Usually CARRY OXYGEN-RICH BLOOD.
• THE AORTA WITH A DIAMETER OF 2.5 cm, IS THE
  LARGEST ARTERY IN THE BODY.
• As the Aorta travels away from the Heart, it
  branches into smaller Arteries

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What are Capillaries?

• The Walls of the Capillaries consist of only one
  layer of cells, making it easy for Oxygen and
  Nutrients to DIFFUSE FROM THE BLOOD INTO THE
  TISSUE.
• Forces of Diffusion drive CO2 and waste products
  from the tissue into the Capillaries.
• Capillaries are extremely NARROW Blood Cells
  moving through them must pass in Single file.

http//www.innerbody.com/anim/blood.html
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What are Veins?

• BLOOD MOVES FROM CAPILLARIES INTO THE VEINS.
• COLLECT Blood from every part of the Body and
  CARRY it Back to the HEART.
• thinner and less elastic than Arteries. 
• contain Valves that maintain the one direction
  flow of Blood.  This is important where Blood
  must flow against the Force of Gravity.

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Circulatory System
The Heart
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The Heart

• Hollow and Muscular
• Involuntary control
• Contracts at regular intervals
• Moves blood through circulatory system
• Myocardium cardiac muscle tissue
• http//www.smm.org/heart/heart/steth.htm

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How Does the Heart Beat?

• Sinoatrial Node (pacemaker)
• Right atrium
• Bundle of nerve cells
• Begin the contraction (of the atria)
• Atrioventricular Node
• Right ventricle
• Passes impulse to ventricles
• Causes ventricles contract

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What happens when your pacemaker doesnt work?
You get an Artificial Pacemaker - a medical
device designed to regulate the beating of the
heart.
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How does contraction of the heart work?

• Phase 1 Systole
• Contraction
• Ventricles contract, closing the AV valves and
  opening the SL valves to pump blood out of the
  heart
• LUB (AV valves closing)

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Then what?

• Phase 2 Diastole
• Relaxation
• Ventricles relax, SL valves close, AV valves open
• Blood fills the ventricles
• DUP (closure of SL valves)

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Cardiac Cycle Animation

• http//www.guidant.com/condition/heart/heart_blood
  flow.shtml

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What is Blood Pressure?

• Fluid pressure that blood exerts against vessel
  walls
• Highest in the aorta
• Normal 120/80
• Systolic/diastolic